1. Field of the Invention
The present invention relates to a garbage disposal apparatus, and more particularly to a garbage disposal apparatus having a garbage processing chamber adapted to decomposition, using microorganisms.
2. Related Art
Garbage can be disposed of by both a dry method and a decomposition method using microorganisms. The dry method involves removing water in the garbage, and gas being generated from the garbage when the water is evaporated. The gas contains components selected from nitrogen compounds, such as ammonia and amine, sulfur compounds, such as methyl sulfide, methyl mercaptan and methyl disulfide, and aldehydes. On the other hand, the decomposition method using microorganisms is able to decompose the garbage into water, carbon dioxide and ammonia if the decomposition is completely performed. However, the adjustment of temperature, the amount of retained water and that of oxygen to control an optimum state for microorganisms to decompose the garbage, cannot easily be performed. Therefore, a malodorous gas similar to that generated with the dry method, is generated.
The malodorous components have varying thresholds for respective components. The threshold means a concentration limit at which a distinction from odorless air cannot be perceived. Gas having a threshold of 0.001 ppm cannot be distinguished from odorless air if the concentration is 0.001 ppm or lower. That is, the gas does not smell. If a malodorous component of 1 ppm having a threshold of 0.001 ppm is contained in the gas, the component is required to have a concentration of 1/1000 or lower. The simplest method to make the gas an odorless gas is to dilute the malodorous component 1000 times.
If garbage of the foregoing type is processed by the decomposition method using microorganisms, the gas generated mixedly contains components, such as ammonia, which are contained in a large quantity and which have relatively large thresholds, and components, such as sulfur components, which are contained in a small quantity and which have significantly small thresholds. For example, ammonia contained in the generated gas at about 100 ppm has a threshold of about 10 ppm. If removal by dilution to 1/10 is performed, the odor of ammonia can be prevented. On the other hand, the overall portion of the generated gas is a large value of about 5000 (the diluting magnification at which a distinction from odorless air cannot be perceived). Therefore, dilution to 5000 times is required to make the malodorous component above be perceived as odorless.
Therefore, if garbage is processed by the decomposition method using microorganisms and gas generated during the process is made to be odorless, dilution to 5000 times is required or the malodorous component must be reduced to 1/5000. The dilution of 5000 times requires a large scale air fan. If activated charcoal is used in the removal process, ammonia generated in a large quantity is adsorbed by the activated charcoal. Thus, the adsorption life-time is too short. If a catalyst is used in the purifying the process, a large quantity of catalyst is required to purify ammonia. Moreover, the gas must be heated to high temperatures in order to cause the catalyst to exhibit its functions. In addition, a large running cost is required. Also a purifying process using ozone requires a large size ozone generator and a large quantity of ozone decomposing catalyst.